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The first speakers with high-end pretensions that I ever owned were the Magneplanar Tympani 1Ds, bought at a hippie place in Dallas called Hungry Ear (you can imagine their logo). The Maggies measured 6’H x 4’W x 1”D and made great bass down to about 40Hz, after which they disappeared from action. The manager of Hungry Ear loved the 1Ds, but he was also a bass fan. Taking an idea from Bud Fried’s IMF Professional Monitor, he loaded two KEF oval woofers into a stout transmission line and suddenly had the quickest, deepest bass imaginable. Granted, building the folded transmission line into a subwoofer box was a feat bordering on engineering genius, but his speakers magically brought that 20-40Hz octave seamlessly into play. At 40Hz, the manager’s sub needed only about 1W to make 100dB at 1m, but he drove it a lot harder than that by using an Audio Research D-150 power amplifier. It made absolute thunder -- something like 120dB at 25Hz. There was one small problem: They were huge. He should have called them the EarQuakes.

But people didn’t buy subwoofers in those days. Finally, he focused on designing and building a stereo pair of speakers, each of which had a woofer system almost as good as his subwoofer, and which he matched to a half dozen or so planar magnetic panels. Then, like most speaker designers, he kept changing them and changing them. If he’d just stuck with his EarQuake sub, he could still be selling them.

Anyway, I couldn’t afford the EarQuake. For that last octave of low bass, I would have had to pay about $7000, which today would be equivalent to about $25,000. Yeowchhh! So I followed the received wisdom of the time: If I could position my main speakers at the precisely correct angles in the perfect locations, I would magically unlock the bottom octave. It’s hard to disprove such a statement -- thus my hundreds of hours spent on knees and elbows, shoving my speakers into different places, tilting them to just the perfect cant. Do you see why I’m such a fan of Audyssey’s room-equalization software?

I tell you all this ancient history because the subject of today’s communiqué, Wisdom Audio’s Sage Series SCS powered subwoofer ($4000 USD), is the first sub that I’ve used that reminds me of the EarQuake.

The Sage Series SCS

Wisdom Audio has nicknamed their Sage Series SCS powered subwoofer the “Suitcase Sub.” To me, suitcase implies easy portability, but this gem of a sub is way too heavy and awkwardly shaped for that. Its silly nickname aside, in the SCS form and function are unquestionably in a dance that gives audiophiles a profound amount of bass from a 7"-thick package. Sound interesting?

Actually, the SCS does vaguely resemble luggage, though I’m not sure even Shaquille O’Neal could lug a suitcase of this shape and weight. To make the SCS somewhat hideable, Wisdom has fixed its depth at 7". Otherwise, it measures about 2’ by 3’ and weighs a hefty 70 pounds. But here’s the important point: Imagine figuring out a way to make a 400W amp and two 5” x 7.5” oval woofers (which together have just about the same radiating surface area of a single 13” woofer) pound out 25Hz at 120dB! That’s what Wisdom claims the SCS can do.

But I’m almost hesitant to say why the SCS reminds me so much of the Hungry Ear EarQuake of long ago. It’s because the SCS is so fast. Imagine me hanging my audiophile head in shame as I try to explain how “fast” this subwoofer is.

Come on, Wes. Subwoofers aren’t fast. All sound is propagated at roughly 1130 feet per second, with only incremental variations in speed due to changes in humidity and temperature. And anyway, the bottom octave of 20-40Hz has wavelengths that are 28 to 56 feet long. In most rooms, you’ll be hearing sounds reflected off a wall before you notice the speed of the note’s propagation. Even if the outputs of the main speakers and sub are perfectly time-aligned and you’ve trained yourself to be picky about such a thing, what most folks mean when they say that a subwoofer is “fast” is that the mains and sub(s) are participating in a sonic dance that their ears find pleasurable.

Great loudspeakers come in all different types of enclosures. I like transmission-line designs, not because they’re fast but because they sound effortless. Speakers loaded with a transmission line put almost zero additional pressure on a driver other than the force of its suspension system. You have to feed it enough power to overcome the inertia of the drive-units and get them moving, but at least you don’t have to stretch air. Take a sealed device like a Sunfire subwoofer, a 13” cube. It requires a huge amount of power because its sealed box means that air must be literally stretched to get it to make sound. Stretching air is an unnatural act, and Mother Nature exacts penalties for committing unnatural acts. Actually, I can just imagine the Sunfire’s inventor, Bob Carver, getting upset over that last line. OK, Bob, I’m kidding. I know the proper word is rarefaction, not stretching.

What about bass-reflex subwoofers -- the types that have a port or slot tuned for the woofer? While it’s tempting to think that you don’t have rarefaction artifacts with a bass-reflex woofer, in fact you do -- at some combination of frequency and amplitude the speaker, like a gasping sprinter, demands that more air be moved into and out of its enclosure than the port can provide. When it can’t quite get enough air, it compresses and distorts.

To me, the freedom of a transmission-line woofer (and midrange, for that matter) from rarefaction, and its minimizing of the effort required to make sound, are parts of what make them sound “fast.” Effortlessness is also what makes some amplifiers sound fast. It’s what makes your eyes relax when you’re watching a video display that’s doing its thing correctly. For me, effortless is one of the most positive adjectives that can be used to describe an audio or video component.

Of course, most A/V manufacturers aren’t content with saying they’re doing a good job of implementing an old technique, such as a transmission-line enclosure. So Wisdom has created and trademarked a design they call Regenerative Transmission Line. Their own succinct description should clarify exactly why their transmission line is different:

We start with a 1/4-wave direct resonator fully dominating at 20Hz, and move to approximately 30Hz where the direct resonator shares its modal activity equally with the 1/2-wave regenerator, and then move on to 40Hz wherein the 1/2-wave regenerator mode fully dominates, and as we move up in frequency we transition to shared modalities at approximately 50Hz, with full direct resonator mode dominating again at 60Hz, and then the transition starts over again.

Got that? Explain it to me when you do. I spent over a half hour on the phone with Jon Herron, Wisdom’s VP of Sales, to get a fuller understanding. Their goal is to recombine the back- and front-wave propagation from each drive-unit in a way that reduces distortion and increases low-frequency amplitude. Since the back and front waves are out of phase by definition, they normally tend to cancel each other out. Wisdom claims that not only do their front and back waves not cancel out, but, due to the length and volume of their transmission line, one side in fact potentiates the other. The website www.DIYsubwoofer.org similarly defines a transmission-line system as:

A waveguide system in which the guide reverses the phase of the driver’s rear output, thereby reinforcing the frequencies near the driver’s Fs. Transmission lines tend to be larger than the other systems, due to the size and length of the line required by the design. The payoff is an extended low-end response and a characteristic sound that’s appealing to many.

I am one of those many fans of transmission-line systems. Although I might be skeptical about Wisdom’s direct-resonating modal wave-regeneration stuff, one thing is certain: It works.

Listening

Subwoofers should be heard or felt and not seen, but at least the Sage Series SCS is an attractive-looking slab. It has three ports for letting the sound out of the box: You pick the one that best suits your room and system and leave the other two sealed. The SCS is designed by Wisdom to fit behind a sofa, under a coffee table, behind risers in a home theater, or anywhere else it will fit. Mine went just under the center-channel speaker. If you intend to use it as part of a home theater, it requires only a wall outlet, and a single-ended RCA or balanced XLR cable to link it to your processor. For two-channel purists, Wisdom offers the outboard SC1 system controller with Audyssey room correction. And if your room is well designed and has good acoustics, you could probably make the SCS work quite nicely with a pair of speakers by merely adjusting the sub’s volume and crossover controls.

I inserted the SCS in my home-theater system, turned on the Audyssey software, and was surprised right away by the low-frequency cutoff. Every other subwoofer I’ve had in my system has shown a decent amount of response above 200Hz. This doesn’t matter in a home theater, because the room-correction software will clamp it down. But the SCS stopped anything above bass from coming out. Maybe it had to do with that 1/4-wave direct resonator dominating that modal activity of the 1/2-wave regenerator? I have no idea, but one thing I do know: Because it really outputs only bass, the SCS would be much easier to integrate into a prime two-channel system whose owner didn’t want to use room-correction software.

When I saw how thin the SCS was, my first desire was to throw at it films that overload normal woofers. My favorite recent barnstormer is Sucker Punch,which we’d seen at the Texas-size IMAX in Austin. This movie has so many plot holes that at times it’s incomprehensible, but if you just sit back and go with it, wow! On the Blu-ray edition, the dragon sequence is a torture test for an entire home-theater system, and I pushed the THX Level all the way to about +4. The SCS shook the house much harder than most normal woofers would, yet not once did it complain. The fact that its two little oval cones were making all that sound was amazing. Ditto for the opening sequences of both Dinosaur and Transformers: Revenge of the Fallen. Given the mayhem in those scenes, I thought the SCS would start to compress or distort the sound -- but at full volume, both sequences sounded clean.

The folks at Linn used to talk about “tuneful bass,” and I was most curious to hear if the SCS had that musical ability. Listening to the remix on Sucker Punch of “Army of Me” made me want to hear Björk’s original version, on Post (CD, One Little Indian TPLP51CDL) --but it just didn’t have the same impact, so I bought the soundtrack disc (CD, Water Tower Music WTM39229). The bass-synth arpeggio is so much bone-crushing fun, and had me wishing for Björk’s old days as a raver.

From there I went to my standard for orchestral impact: the soundtrack to Mission: Impossible (CD, Point Music 454 525-2). Now, don’t get me wrong -- this recording was closely miked, and has virtually no ambience or even any third dimension, let alone a viable soundstage. Every instrument sounds as if it has ten microphones within a half inch of its sound hole. But because it’s so closely recorded, the music’s impact is virtually unmatched (note: Amazon.com lists several used copies for under $1). I brought over a friend who’d been the Artistic Administrator of the Houston Symphony, and has heard orchestras from in front of, behind, and on the stage. He told me that he’d never heard the decay of a bass drum’s sound reproduced with such realism.

My poor friend nearly jumped out of his seat when I played Sarah McLachlan’s version of “Unchained Melody.”She deconstructs the song, removing and replacing the melody altogether. But the opening crash is kind of like falling asleep at the park and being startled awake by a bass-drum thwack six inches from your head. We both loved “Too Rich for My Blood,” from Patricia Barber’s Café Blue (CD, Premonition/Blue Note PREM-733702), with that realistic and very woody-sounding bass solo. The SCS caught both its impact and power without losing its acoustic sound.

Adam Young of Owl City has produced a delightful body of music in just three years, and one reason I like him is that he regularly uses the deep-bass potential of synthesizers. Two of his songs that get maximum airplay at our house are “I’ll Meet You There” (from Maybe I’m Dreaming, CD, Sky Harbor B0012858-02) and “On the Wing” (from Ocean Eyes, CD, Universal 0602527108223). Again, no matter how loud I cranked up either track, the SCS never seemed to lose steam.

Conclusions

Whenever I write a positive review, I’m asked the same question: “Did you buy it?”

I was completely impressed with Wisdom Audio’s Sage Series SCS -- it offered all the performance I could ask for. In fact, I rate it up there with the JL Audio Fathom f112, which is high praise indeed. But it doesn’t fit any of my room’s awkward spaces, and the subwoofer I own, a B&W CT SW15 (no longer made), offers everything I need, from size to performance. Otherwise, I would have been sorely tempted.

The SCS has only one downside: its price. For $4000, you can buy a lot of other great subwoofers. But accurate subs that can recede from view are rare, and people seem willing to spend more for speakers they can hide away. When you compare the SCS to other thin subs, like high-end in-walls such as JLA’s Fathom IWS-SYS-1 ($4500) or BG Radia’s BGX-S12B ($6950), $4000 doesn’t seem quite so costly.

If a big square box suits your needs, there are a few other subs on the market that will do just as well as the Sage Series SCS, and several with lower prices. But compared to others that you can potentially hide away, the Wisdom is a fair bargain. If that’s what you need, I give the SCS my highest recommendation.